Terminology, Definitions, and Classification of Chronic Pulmonary Emphysema and Related Conditions: A REPORT OF THE CONCLUSIONS OF A CIBA GUEST SYMPOSIUM

At present the word emphysema is used to indicate various morbid states of the lung differing widely in their pathology, symptomatology, and prognosis.This results in confusion and misunderstanding between investigators working in different centres and in different branches of medicine and thus retards advance in knowledge of a group of common and often serious disabling diseases.The purpose of the symposium, the conclusions of which are reported here, was to see whether a group of British investigators could agree upon provisional definitions, classifications, and terminology, and suggest lines of investigation which might clarify obscurities which at present impede the formulation of a satisfactory system of classification.Individual contributions to the symposium were presented informally and were not intended for publication.At the end of the meeting certain provisional conclusions and proposals were formulated.These were subsequently recon- sidered, modified by a drafting committee, and finally approved (with minor reservations) by all the participants.The proposals are provisional and should not be regarded as committing any of the participants to any particular view.They are published in order to encourage people to use defined terms in making pathological, clinical, and functional assessments, to investigate the reproducibility of these assessments in the hands of the same and different observers, and to determine their significance and validity by comparing the results of the different types of assessment with one another.The participants thought this was necessary before any final definition or classification of emphysema itself or the conditions that may be associated with it could *The symposium was held on September 24-26, 1958.